Method of adjustment for a north-south automatic transaxle

ABSTRACT

The present invention is a method of adjusting backlash for a north-south transaxle. The method includes the steps of forming a case having a first passageway extending longitudinally and a second passageway spaced from the first passageway and being generally parallel to the first passageway and extending longitudinally and a cavity at one end of the second passageway having an opening generally perpendicular to the passageway. The method also includes disposing a transmission assembly in the first passageway and a transfer assembly in the second passageway and a differential assembly in the cavity and engaging the transfer assembly. The method further includes preloading the differential assembly, determining the amount of backlash between the differential assembly and transfer assembly, and adjusting the backlash between the differential assembly and transfer assembly.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a transaxle primarilyintended for motor vehicle use, and more particularly, to a north-southautomatic transaxle for a motor vehicle.

2. Description of the Related Art

Generally speaking, motor vehicles require three basic components. Thesecomponents include a power plant (such as an internal combustionengine), a power train and wheels. The internal combustion engineproduces force by the conversion of chemical energy in a liquid fuelinto mechanical energy of motion (kinetic energy). The function of thepower train is to transmit this force to the wheels to provide movementof the motor vehicle.

The power train's main component is typically referred to as the"transaxle". Engine torque and speed are converted in the transaxle inaccordance with the tractive-power demand of the motor vehicle. Thetransaxle is also capable of controlling the direction of rotation beingapplied to the wheels, so that the motor vehicle may be driven bothforward and backward.

Typically, the transaxle includes two basic components. These componentsare a transmission and differential. The transmission is generallyreferred to as a manually actuated or automatic transmission. Anautomatic transmission is designed to take automatic control offrictional units, gear ratio selection and gear shifting. An example ofsuch an automatic transmission is disclosed in U.S. Pat. No. 4,875,391,issued on Oct. 24, 1989, to Leising, et al. The differential istypically an arrangement of gears forming an epicyclic train forconnecting two shafts or axles for the wheels in the same line, dividingthe force from the transmission equally between them, and permitting oneshaft to revolve faster than the other.

In recent years, transaxles have been orientated in an east-west manneror generally perpendicular to a longitudinal axis of the motor vehicle.While this orientation provides several advantages, it has been desiredto orientate the transaxle in a north-south manner or generally parallelto the longitudinal axis of the motor vehicle. It has also been desiredto provide a north-south orientated transaxle which is more compact andmeets specific needs and requirements of today's motor vehicle design.

SUMMARY OF THE INVENTION

It is, therefore, one object of the present invention to provide atransaxle for a motor vehicle having a north-south orientation.

It is another object of the present invention to provide a north-southautomatic transaxle for a motor vehicle.

It is yet another object of the present invention to provide a transferassembly between a transmission and differential of a transaxle and amethod of assembling the transfer assembly.

It is still another object of the present invention to provide aretaining arrangement for the transmission and transfer assembly.

It is a further object of the present invention to provide thermalcompensation of bearing preload for the differential of the transaxle.

It is yet a further object of the present invention to provide a methodof adjusting the engagement between the transfer assembly anddifferential.

It is a still further object of the present invention to provide alubrication system for lubricating a bearing of the transfer assembly.

It is another object of the present invention to provide an assembly forretaining a connector to the transaxle.

To achieve the foregoing objects, the present invention is an automatictransaxle for a motor vehicle including a transmission assembly havingan orientation generally parallel to a longitudinal axis of the motorvehicle. The transaxle also includes a transfer assembly spacedlaterally and generally parallel to the transmission assembly. Thetransaxle further includes a differential assembly cooperating with thetransfer assembly.

The present invention is a method of adjusting backlash for anorth-south transaxle. The method includes the steps of forming a casehaving a first passageway extending longitudinally and a secondpassageway spaced from the first passageway and being generally parallelto the first passageway and extending longitudinally and a cavity at oneend of the second passageway having an opening generally perpendicularto the passageway. The method also includes disposing a transmissionassembly in the first passageway and a transfer assembly in the secondpassageway and a differential assembly in the cavity and engaging thetransfer assembly. The method further includes preloading thedifferential assembly, determining the amount of backlash between thedifferential assembly and transfer assembly, and adjusting the backlashbetween the differential assembly and transfer assembly. The transaxleincludes other specific features to be described.

One advantage of the present invention is that an automatic transaxle isprovided for a motor vehicle having a north-south orientation generallyparallel to a longitudinal axis of the motor vehicle. Another advantageof the present invention is that the transaxle has a transfer assemblybetween a transmission assembly and differential assembly. Yet anotheradvantage of the present invention is that a retaining arrangement isprovided which allows sprocket wheels and a transfer chain to be removedand installed without disturbing bearings for the transmission assemblyand transfer assembly. Still another advantage of the present inventionis that the transaxle case and differential assembly are made of analuminum material to provide thermal compensation of bearing preload forthe differential assembly. A further advantage of the present inventionis that a lubrication system is provided in the differential assemblyfor lubricating a bearing of the transfer assembly. A still furtheradvantage of the present invention is that an assembly is provided toretain the connector to the transaxle case to allow removal andinstallation of a solenoid assembly without disturbing the connector.

Other objects, features and advantages of the present invention will bereadily appreciated as the same becomes better understood after readingthe subsequent description taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a north-south automatic transaxle according tothe present invention.

FIG. 2 is an elevational view of the transaxle of FIG. 1.

FIG. 3 is an end view of the transaxle of FIGS. 1 and 2 rotatedapproximately one hundred eighty degrees.

FIG. 4 is a fragmentary view of the transaxle of FIGS. 1 and 2.

FIG. 5 is a partial enlarged view of a portion of FIG. 4 illustrating atransfer shaft being installed.

FIG. 6 is a view similar to FIG. 5 illustrating the transfer shaftinstalled.

FIG. 7 is a view similar to FIG. 6 illustrating the transfer shaftinstalled and retained in the transaxle.

FIG. 8 is an enlarged view of a portion of the transaxle of FIG. 4illustrated in operational relationship with an adjustment assembly.

FIG. 9 is an enlarged view of a portion of the transaxle of FIG. 2 witha cover member removed.

FIG. 10 is a sectional view taken along line 10--10 of FIG. 9.

FIG. 11 is a fragmentary view of the transaxle of FIGS. 1 and 2.

FIG. 12 is a partial exploded perspective view of a portion of FIG. 11.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring to FIGS. 1 through 4, a transaxle 10, according to the presentinvention, is illustrated for a motor vehicle (not shown) such as anautomotive vehicle. The transaxle 10 has a north-south or longitudinalpowertrain orientation generally parallel to a longitudinal axis of themotor vehicle. The transaxle 10 includes a case 12, transmissionassembly 14, transfer assembly 16 and differential assembly 18. The case12 houses the transmission assembly 14, transfer assembly 16 anddifferential assembly 18. The transmission assembly 14 converts torqueand speed from an engine (not shown) such as an internal combustionengine of the motor vehicle and produces a torque output. The transferassembly 16 transfers the torque output from the transmission assembly14 to the differential assembly 18. The differential assembly 18 dividesthe torque output and transmits the resultant torque to wheels (notshown) of the motor vehicle.

The case 12 has a first passageway 20 extending longitudinallytherethrough to house the transmission assembly 14. The case 12 also hasa second passageway 22 spaced laterally and substantially parallel tothe first passageway 20 and extending longitudinally therethrough tohouse the transfer assembly 16. The case 12 includes a cavity 24 at oneend of the second passageway 22 to house the differential assembly 18.The cavity 24 is closed by a differential cover member 26 connected bysuitable fastening means such as bolts 28 to a side of the case 12. Thecase 12 also includes a rear cover member 30 connected by suitablefastening means such as bolts 32 to a rear or output end of the case 12to enclose the ends of the transmission assembly 14 and transferassembly 16. The Case 12, differential cover member 26 and rear covermember 30 are from a similar metal material such as an aluminummaterial.

The transmission assembly 14 is an automatic transmission of the typedisclosed in U.S. Pat. No. 4,875,391 to Leising et al. and assigned tothe same assignee at the present invention, the disclosure of which ishereby incorporated by reference. As illustrated, the transmissionassembly 14 includes a shaft portion 34 of a rear carrier of a gearassembly (not shown) disposed in the first passageway 20. The shaftportion 34 extends longitudinally and is rotatably supported by abearing 35 such as a tapered roller bearing in the case 12. Thetransmission assembly 14 includes a nut 36 which threadably engages athreaded portion 37 on the shaft portion 34 to retain the shaft portion34 and bearing 35 in the case 12. The transmission assembly 14 alsoincludes an output sprocket wheel 38 connected by a spline connection 39to the shaft portion 34. The output sprocket wheel 38 is retained to theshaft portion 34 by suitable retaining means such as a wave washer 40and a snap ring 42. The transmission assembly 14 further includes aspacer 44 disposed between the nut 36 and the output sprocket wheel 38to align the output sprocket wheel 38 with a transfer sprocket wheel 78to be described.

The transfer assembly 16 includes a transfer shaft 46 disposed in thesecond passageway 22. The transfer shaft 46 has a head portion 48 andshaft portion 50. The head portion 48 has a generally frustoconicalshape with a plurality of teeth 52 spaced circumferentially thereaboutto form a pinion gear. The shaft portion 50 extends longitudinally fromthe head portion 48 and is rotatably supported in the second passageway22 by front and rear bearings 54 and 56. The bearings 54, 56 are,preferably, tapered roller bearings having a cup 58 engaging the case 12and a cone 60 with tapered rollers 62 disposed about the shaft portion50 and engaging the cup 58. The cup 58 and cone 60 have tapered matingsurfaces extending inwardly at an angle toward the transfer shaft 46. Itshould be appreciated that the front and rear bearings 54 and 56 areconventional and allow the transfer shaft 46 to rotate relative to thecase 12.

The transfer assembly 16 also includes front and rear seals 66 and 68disposed in the second passageway 22 and about the shaft portion 50 andengaging the case 12. The front and rear seals 66 and 68 abut each otherand are located at a predetermined position along the shaft portion 50for a function to be described. The transfer assembly 16 includes afluid baffle 72 disposed in the second passageway 22 and about the shaftportion 50 and engaging the case 12. The fluid baffle 72 is locatedadjacent the rear bearing 56 to prevent fluid entering the secondpassageway 22 from the rear bearing 56.

The transfer assembly 16 further includes a nut 74 which threadablyengages a threaded portion 76 on the transfer shaft 46 to retain thetransfer shaft 46 and bearings 54, 56 in the case 12. The transferassembly 16 also includes a transfer sprocket wheel 78 connected by aspline connection 79 to the shaft portion 50 of the transfer shaft 46.The transfer sprocket wheel 78 is retained to the transfer shaft 46 bysuitable retaining means such as a wave washer 80 and a snap ring 82.

Referring to FIGS. 3 and 4, the transaxle 10 also includes a transferchain 84 disposed about the output sprocket wheel 38 and transfersprocket wheel 78 to connect the sprocket wheels 38 and 78 together. Thetransaxle 10 further includes a snubber 85 connected to the case 12 bysuitable fastening means such as bolts 86. Preferably, the snubber 85 ismade of an elastomeric material and is located on the tension or powerside of the transfer chain 84. The snubber 85 dampens and resistsexcursions or vibrations of the transfer chain 84 due to a verticalcomponent of rotation. It should be appreciated that rotation of theshaft portion 34 and output sprocket wheel 38 moves the transfer chain84, in turn, rotating the transfer sprocket wheel 78 and transfer shaft46. It should also be appreciated that the transfer chain 84 andsprocket wheels 38, 78 eliminate the need to use transfer gears, therebymaking the transaxle 10 quieter and more durable.

Referring to FIGS. 5 through 7, a method of assembling the transferassembly 16, according to the present invention, is illustrated. Themethod includes installing the front bearing 54 in the case 12. The cup58 of the front bearing 54 is pressed or seated along the secondpassageway 22 in the case 12. Next, the cone 60 of the front bearing 54is disposed on the cup 58. A tool, such as a dial indicator (not shown),is used to measure the depth of the transfer shaft 46 and determine thethickness of a shim 87a (FIG. 4) that will be required between the headportion 48 and the bearing cone 60. Next, the shim 87 is disposed aboutthe shaft portion 50 and seated against the head portion 48. The cone 60is removed from the case 12, disposed about the shaft portion 50, andpressed or seated against the head portion 48.

As illustrated in FIG. 5, the method includes installing the transfershaft 46 with shim 87 and cone 60 in the case 12. The shaft portion 50is inserted into the cavity 24 and rotated to enter the secondpassageway 22. The shaft portion 50 is extended through the secondpassageway 22 until the cone 60 seats against the cup 58 of the frontbearing 54. As illustrated in FIG. 6, the method includes installing thefront and rear seals 66 and 68 and fluid baffle 72 in the case 12. Thefront and rear seals 66 and 68 are disposed about the shaft portion 50.A tool, such as a press (not shown), is used to install the front andrear seals 66 and 68 at the proper location along the shaft portion 50.The fluid baffle 72 is disposed about the shaft portion 50 and installedin the case 12 at the proper location along the shaft portion 50.

Next, the method includes installing the rear bearing 56 in the case 12.The cup 58 of the rear bearing 56 is pressed or seated along the secondpassageway 22 in the case 12. A preload shim 87b is disposed about theshaft portion 50 and seated against a shoulder of the shaft portion 50.The cone 60 is disposed about the shaft portion 50 and pressed onto theshaft portion 50 until seated against the cup 58 and preload shim 87b.As illustrated in FIG. 7, the nut 74 is threaded onto the threadedportion 76 and tightened to obtain a predetermined torque. After thepredetermined torque is obtained, the nut 74 is staked to the transfershaft 46.

Next, the method includes installing the sprocket wheels 38, 78 andtransfer chain 84. The transfer chain 84 is disposed about the sprocketwheels 38, 78 and a chain spreader (not shown) is disposed between thesprocket wheels 38, 78 and adjusted to apply pressure to the transferchain 84 and form an assembly. The sprocket wheels 38, 78 are then slipfitted onto the shaft portions 34, 50, respectively. The chain spreaderis adjusted to release the pressure on the transfer chain 84 and isremoved. The wave washers 40, 80 and snap rings 42, 82 are disposedabout the shaft portions 34, 50, respectively. The chain snubber 85 isthen installed with the bolts 86. Finally, the rear cover member 30 isinstalled with bolts 32. It should be appreciated that the spacer 44 maybe replaced with a different thickness to ensure that the sprocketwheels 38, 78 are at the same height prior to installing the sprocketwheels 38, 78 and transfer chain 84.

Referring to FIGS. 4 and 8, the differential assembly 18 includes a ringor hypoid gear 88 disposed in the cavity 24 and having a plurality ofteeth 90 engaging the teeth 52 of the transfer shaft 46. Thedifferential assembly 18 also includes a differential case assembly,generally indicated at 92, disposed in the cavity 24 and connected tothe hypoid gear 88 by suitable fastening means such as bolts 94. Thedifferential assembly 18 further includes inner and outer stub or axleshafts 96 and 98 extending into the cavity 24 and differential caseassembly 92. The inner stub shaft 96 extends laterally orperpendicularly to the longitudinal axis of the transaxle 10 and isrotatably supported by bearings (not shown) in the case 12. The outerstub shaft 98 is shorter in length than the inner stub shaft 96. Theouter stub shaft 98 is aligned with inner stub shaft 96 and extendslaterally or perpendicularly to the longitudinal axis of the transaxle10. It should be appreciated that the stub shafts 96, 98 are operativelyconnected to the wheels of the motor vehicle.

The differential assembly 18 includes inner and outer differentialadjusters 100 and 102 disposed about the inner and outer stub shafts 96and 98, respectively, and engaging the case 12. The differentialadjusters 100, 102 are generally annular and made of a metal materialsuch as an aluminum material similar to the differential cover member26. The differential adjusters 100, 102 have a threaded portion 104which threadably engages corresponding threaded portions 106 on the case12 to allow rotation and lateral adjustment of the differentialadjusters 100, 102 relative to the case 12. The differential assembly 18includes inner and outer adjuster lock brackets 108 and 110 connected tothe case 12 by suitable fastening means such as bolts 112 and whichengage the differential adjusters 100, 102 to prevent rotation of thedifferential adjusters 100, 102. The differential assembly 18 furtherincludes inner and outer seals 114, 116 disposed between thedifferential adjusters 100, 102 and stub shafts 96, 98 to prevent fluidfrom exiting the differential assembly 18.

The differential assembly 18 also includes inner and outer bearings 118and 120 disposed between the differential adjusters 100, 102 anddifferential case assembly 92 to rotatably support the differential caseassembly 92 in the cavity 24. The bearings 118, 120 are, preferably,tapered roller bearings having a cup 122 engaging the differentialadjusters 100, 102 and a cone 124 with tapered rollers 126 disposedabout the differential case assembly 92 and engaging the cup 122. Itshould be appreciated that the bearings 118, 120 are conventional andallow the differential case assembly 92 to rotate relative to thedifferential adjusters 100, 102 and case 12.

The differential case assembly 92 includes inner and outer differentialcarriers 128 and 13 which form a central cavity 132 therein with innerand outer apertures 134 and 136 at each end. The stub shafts 96, 98extend through the apertures 134, 136 and into the central cavity 132.The differential carriers 128, 130 are made of a metal material such asa cast iron or aluminum material.

The differential case assembly 92 also includes a pinion shaft 138disposed in a longitudinal aperture 140 extending through the innerdifferential carrier 128. The pinion shaft 138 is secured to the innerdifferential carrier 128 by suitable means such as a pin 144. Thedifferential case assembly 92 further includes front and rear piniongears 146 and 148 disposed in the central cavity 132 and about thepinion shaft 138. The front and rear pinion gears 146 and 148 have agenerally frustoconical shape with a plurality of teeth 150 and 152,respectively, spaced circumferentially thereabout. The differential caseassembly 92 also includes bearing pads 154 disposed between the piniongears 146, 148 and the inner differential carrier 128. It should beappreciated that the pinion gears 146, 148 may rotate about the pinionshaft 138.

The differential case assembly 92 also includes inner and outer sidegears 156 and 158 disposed material, thermal compensation is provided toequalize bearing preload over a temperature operating range. In themethod, a preload or dead weight 170 having a hook portion 172 engagescorresponding slots 174 in the differential cover member 26. A first ram(not shown) pulls the dead weight 170 in the direction indicated by thearrow and a second ram 176 pushes on the outer differential adjuster 102to stretch the differential cover member 26. It should be appreciatedthat distance sensors (not shown) are placed on the differential covermember 26 to record the stretch and an additional sensor (not shown) isplaced on the inner stub shaft 96 to measure preload and backlash.

The method includes determining the amount of backlash or engagementbetween the teeth 52 of the transfer shaft 46 and the teeth 90 of thehypoid gear 88. The amount of stretch of the differential cover member26 is compared to predetermined plots of stretch versus preload (i.e.,dead weight). At a preload less than or greater than a predetermined ortarget preload, backlash is adjusted by rotating the differentialadjusters 100, 102 and moving the differential adjustors 100, 102laterally in tandem, in turn moving the cups 122, to achieve the targetpreload. It should be appreciated that the inner and outer adjusters 100and 102 are rotated to move the hypoid gear 88 closer to or further awayfrom the head portion 48 of the transfer shaft 46 by corresponding tools178 and 180, respectively, such as a racket with spaced teeth whichengage spaced recesses in the differential adjusters 100, 102. It shouldalso be appreciated that the differential adjusters 100, 102 areunlocked before adjustment and locked in place after adjustment by theadjuster lock brackets 108, 110. It should further be appreciated thatonce the adjusters 100, 102 are locked in place, the dead weight 170,rams 176 and sensors are removed.

Referring to FIGS. 9 and 10, the transaxle 10 includes a lubricationsystem, generally indicated at 182, in the differential assembly 18 forlubricating the front bearing 54 of the transfer assembly 14. Thelubrication system 182 includes differential fluid in the cavity 24which acts as a sump and is separate from the transmission assembly 14.The lubrication system 182 includes a fluid passageway 184 in the case12 between the cavity 24 and an inlet aperture 186 along the secondpassageway 22. The front and rear seals 66 and 68 are located past theinlet aperture 186 to separate the differential fluid from transmissionfluid of the transaxle 12. It should be appreciated that the seals 66,68 may have a weep hole 187 between them for fluid identificationpurposes during leakage.

In operation, the hypoid gear 88 rotates to act as a pump to movedifferential fluid in the fluid in the central cavity 132. The inner andouter side gears 156 and 158 are connected by a spline connection to theinner and outer stub shafts 96 and 98, respectively, and may be retainedby suitable retaining means such as a "C" shaped clip 160. The inner andouter side gears 156 and 158 have a generally frustoconical shape with aplurality of teeth 162 and 164, respectively, engaging the teeth 150 and152 of the front and rear pinion gears 146 and 148. The differentialcase assembly 92 includes bearing pads 166 disposed between the sidegears 156, 158 and carriers 128, 130. It should be appreciated that thehypoid gear 88 drives the differential case assembly 92 for all gearsand provides input power to the stub shafts 96, 98. It should also beappreciated that the pinion gears 146, 148 and side gears 156, 158 allowthe stub shafts 96, 98 to rotate at different speeds while the motorvehicle is moving.

Referring to FIG. 8, a method for adjusting the engagement or backlashbetween the transfer assembly 16 and differential assembly 18, accordingto the present invention, is illustrated. The method includes preloadingthe bearings 118, 120 and differential cover member 26 of the transaxle10. The preloading is performed at room temperature and since the case12, differential cover member 26, adjusters 100, 102 and differentialcarriers 128, 130 are made of aluminum passageway 184 as indicated bythe arrows. The differential fluid moves along the fluid passageway 184and into the inlet aperture 186. From the inlet aperture 186, thedifferential fluid enters the second passageway 22 and flows between thetapered rollers 162 and through the front bearing 54. Then, thedifferential fluid travels between the teeth 52 in the transfer shaft 46and the teeth 90 in the hypoid gear 88 in the cavity 24.

Referring to FIGS. 11 and 12, a connector assembly, generally indicatedat 188 and according to the present invention, is illustrated inoperational relationship with the case 12 and a solenoid assembly 190.The connector assembly 188 includes a connector 192 connected to asource of electrical power (not shown). The connector 192 has a headportion 194, a flange portion 196, and a body portion 198. The headportion 194 is generally rectangular in shape and has a recess 200extending inwardly from one side for a function to be described. Theflange portion 196 extends laterally from the head portion 194 and has aseal 197 on one side. The body portion 198 is generally rectangular andextends longitudinally from the flange portion 198. The body portion 198extends through an aperture 202 in the case 12 and the seal 197 on theflange portion 196 engages the case 12 adjacent the aperture 202, asillustrated in FIG. 11. It should be appreciated that the aperture 202is orientated at an angle relative to a longitudinal axis of the case12. It should also be appreciated that the flange portion 196 has awidth and length greater than the aperture 202. It should further beappreciated that the free end of the connector 192 is disposed in acorrespondingly shaped cavity (not shown) of a receiver 204 of thesolenoid assembly 190.

The connector assembly 188 also includes a retainer bracket 206 forcooperating with the connector 192. The retainer bracket 206 isgenerally an inverted "L" shape and has an aperture 208 extendingtherethrough. The retainer bracket 206 has a projection 210 extendinglaterally from an upper end of the inverted "L" shape. The projection210 is generally triangular in shape and engages the recess 200 in theconnector 192.

The connector assembly 188 further includes fastener 212 such as bolt toretain the retainer bracket 206 to the case 12. The fastener 212 has ahead portion 214 and a shaft portion 216 extending from the head portion216. The shaft portion 216 has a threaded portion 218 which threadablyengages a threaded aperture 220 in the case 12 adjacent the aperture202.

In operation, the connector 192 is disposed in the aperture 202 suchthat the body portion 198 extends therethrough and the flange portion196 abuts the case 12. The projection 210 of the retainer bracket 206 isdisposed in the recess 200 of the head portion 194 and the aperture 208is aligned with the aperture 220 in the case 12. The fastener 212 isdisposed in the aperture 208 such that the shaft portion 216 extendstherethrough and the threaded portion 218 engages the threaded aperture220. The fastener 212 is tightened by rotating the head 214 to sandwichthe connector 192 between the retainer bracket 206 and case 12.

The solenoid assembly 190 is secured to a valve body (not shown) whichis fastened to the case 12. The valve body is moved toward the case 12such that the body portion 198 is disposed in the receiver 204. Thevalve body is secured to the case 12 by suitable means such as fasteners(not shown). It should be appreciated that the valve body and solenoidassembly 190 may be removed and installed without disturbing theconnector 192 which is retained to the case 12 by the retainer bracket206 and fastener 212.

Accordingly, the transaxle 10 is an automatic transaxle having anorth-south powertrain orientation. The transaxle 10 has a transferassembly 16 between a transmission assembly 14 and differential assembly18. A transfer shaft 46 of the transfer assembly 16 is installed througha differential cavity 24 and into a passageway 22. The transmissionassembly 14 and transfer assembly 16 have corresponding nuts 36 and 74for retaining the shafts and bearings which allow sprocket wheels 38, 78to be installed and serviced without disturbing any bearing setting. Thetransaxle 10 uses an aluminum material for the case 12, differentialcover member 26, differential adjusters 100, 102, and differentialcarriers 128, 130 to provide thermal compensation to equalize bearingpreload over an operating range of the bearings for the differentialassembly 18. The transaxle 10 has a unique method for adjusting thebacklash between the hypoid gear 88 and transfer shaft 46. The transaxle10 has a pump and lubrication system for delivery of differential fluidto the front bearing 54 for the transfer shaft 46. Further, thetransaxle lo has a connector assembly 188 for retaining a connector 192to the case 12 which allows removal and installation of a solenoidassembly 190 without disturbing the connector 192.

The present invention has been described in an illustrative manner. Itis to be understood that the terminology which has been used is intendedto be in the nature of words of description rather than of limitation.

Many modifications and variations of the present invention are possiblein light of the above teachings. Therefore, within the scope of theappended claims, the present invention may be practiced otherwise thanas specifically described.

What is claimed is:
 1. A method of adjusting backlash for a north-southtransaxle, said method comprising the steps of:forming a case having afirst passageway extending longitudinally, a second passageway spacedfrom the first passageway and being generally parallel to the firstpassageway and extending longitudinally, and a cavity at one end of thesecond passageway having an opening generally perpendicular to thesecond passageway; disposing a transmission assembly in the firstpassageway; disposing a transfer assembly in the second passageway;interconnecting the transmission assembly and the transfer assembly fortransferring torque from the transmission assembly to the transferassembly; disposing a differential assembly in the cavity and engagingthe transfer assembly; preloading the differential assembly; determiningthe amount of backlash between the differential assembly and transferassembly; and adjusting the backlash between the differential assemblyand transfer assembly.
 2. A method as set forth in claim 1 including thestep of enclosing the opening of the cavity with a differential covermember.
 3. A method as set forth in claim 2 wherein the step ofpreloading comprises engaging a dead weight with the differential covermember and pulling the dead weight in a direction away from thedifferential cover member.
 4. A method as set forth in claim 3 whereinsaid step of engaging comprises disposing a hook portion of the deadweight in corresponding slots of the differential cover member.
 5. Amethod as set forth in claim 1 wherein said step of determiningcomprises measuring the stretch of the differential cover member andcomparing the amount of stretch to predetermined plots of stretch versuspreload.
 6. A method as set forth in claim 5 wherein said step ofmeasuring comprises sensing the stretch of the differential covermember.
 7. A method as set forth in claim 6 including the step ofplacing sensors on the differential cover member prior to said step ofsensing.
 8. A method as set forth in claim 1 wherein said step ofadjusting comprises rotating inner and outer adjusters of thedifferential assembly and moving the inner and outer adjusters laterallyto move the differential assembly toward and away the transfer assembly.9. A method as set forth in claim 8 including the step of unlocking theadjusters to allow rotation thereof prior to adjusting.
 10. A method asset forth in claim 8 including locking the adjusters relative to thecase to prevent rotation after adjustment thereof.
 11. A method ofadjusting backlash for a north-south transaxle, said method comprisingthe steps of:forming a case having a first passageway extendinglongitudinally, a second passageway spaced from the first passageway andbeing generally parallel to the first passageway and extendinglongitudinally, and a cavity at one end of the second passageway havingan opening generally perpendicular to the second passageway; disposing atransmission assembly in the first passageway; disposing a transferassembly in the second passageway; interconnecting the transmissionassembly and the transfer assembly for transferring torque from thetransmission assembly to the transfer assembly; disposing a differentialassembly in the cavity and engaging the transfer assembly; enclosing theopening of the cavity with a differential cover member; preloading thedifferential cover member; measuring the stretch of the differentialcover member and comparing the amount of stretch to predetermined plotsof stretch versus preload to determine the amount of backlash betweenthe differential assembly and transfer assembly; and adjusting thebacklash between the differential assembly and transfer assembly toachieve a target preload.
 12. A method as set forth in claim 11 whereinsaid step of preloading comprises engaging a dead weight with thedifferential cover member and pulling the dead weight in a directionaway from the differential cover member.
 13. A method as set forth inclaim 12 wherein said step of engaging comprises disposing a hookportion of the dead weight in corresponding slots of the differentialcover member.
 14. A method as set forth in claim 11 including the stepof placing sensors on the differential cover member and sensing thestretch of the differential cover member.
 15. A method as set forth inclaim 11 wherein said step of adjusting comprises rotating inner andouter adjusters of the differential assembly and moving the inner andouter adjusters laterally to move the differential assembly toward andaway the transfer assembly.
 16. A method as set forth in claim 15including the step of unlocking the adjusters to allow rotation thereofprior to adjusting.
 17. A method as set forth in claim 15 includinglocking the adjusters relative to the case to prevent rotation afteradjustment thereof.
 18. A method of adjusting backlash for a north-southtransaxle, said method comprising the step of:forming a case having afirst passageway extending longitudinally, a second passageway spacedfrom the first passageway and being generally parallel to the firstpassageway and extending longitudinally, and a cavity at one end of thesecond passageway having an opening generally perpendicular to thesecond passageway; disposing a transmission assembly in the firstpassageway; disposing a transfer assembly in the second passageway;interconnecting the transmission assembly and the transfer assembly fortransferring torque from the transmission assembly to the transferassembly; disposing a differential assembly in the cavity and engagingthe transfer assembly; enclosing the opening of the cavity with adifferential cover member; engaging a dead weight with the differentialcover member and pulling the dead weight in a direction away from thedifferential cover member; sensing the stretch of the differential covermember, measuring the stretch of the differential cover member andcomparing the amount of stretch to predetermined plots of stretch versuspreload; and rotating inner and outer adjusters of the differentialassembly and moving the inner and outer adjusters laterally to move thedifferential assembly toward and away the transfer assembly to achieve atarget preload.